The markings do look like ones for a parking garage, but they could also be for something else, possibly a new toll booth similar to that at Kings Island given the location of the markings. But, we will just have to wait and see.

New for 2018 at Canada'sWonderland: Lumberjack, FlyingCanoes, and SplashIslandExpansion!

I think the new toll plaza mentioned by Johnlloyd would be very helpful, but I don't know how likely that is... If Disney and Universal are any indication, a parking garage would take a fair while... Based on what I've seen, I'm fairly confident there won't be anything ready for 2018 except perhaps a construction site (two if you count the one in the park).